Fact: Religiously scrub off the day's grime or you're asking for an early onset of wrinkles, spots, and sagging

Side effects from pollution, from the quilted gray air hanging over L.A. to the alarming rise in asthma, can be seriously unpleasant. Now the latest research shows that pollution is also aging our skin. The culprit: an increase in minuscule particles and liquid droplets of pollution in the air so tiny that they lodge in pores. "These environmental impurities destroy skin's natural oils, which act as a protective barrier," says New York dermatologist Dennis Gross. "That leaves skin exposed to free radicals and leads to collagen breakdown, aging, cell damage, redness, and irritation." These toxins also create a physical barrier that prevents treatment products from penetrating. And no one, from the Hamptons to Hampstead, is immune. According to one recent study, more than 80 percent of the world's population now breathes polluted air that exceeds the World Health Organization's air-quality guidelines.

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"Pollution speeds up the development of lines, wrinkles, and dark spots," says New York dermatologist Joshua Zeichner, "and it may also contribute to the development of skin cancers. That's why it's so important to cleanse in a way that removes the particulate matter from your pores." Those on beauty's front lines agree. "If you don't wash your face properly before bed, you are not allowing skin's natural repair process to take place," says Joanna Vargas, a facialist to radiant A-listers like Michelle Williams. "I guarantee you will wake up to puffier eyes, darker circles, breakouts, and less elasticity."

Luckily there are an increasing number of options, from organic balms to ever more advanced sonic cleansing brushes, that get even the tiniest particle out while leaving skin glowing—and more receptive to antiaging serums. Choosing the right method depends on skin type and preference. Among the latest innovations is micellar technology, which enables cleansers to act as makeup remover and toner in one. "Micellar water has droplets, usually oils, suspended in it that help to grab on to debris and wash it away," explains Elizabeth Tanzi, a Washington, D.C., dermatologist. The cleansers, which contain no soap or irritants, are applied to dry skin and wiped off with a cotton ball, making them ideal for sensitive types. Try La Roche-Posay Physiological Micellar Solution ($21) or Avène Micellar Lotion Cleanser ($20). Cleansing balms, with a rich texture that melts on contact, have a large cult following. "They are particularly good for dry or aging complexions," says Amanda Lacey, an in-demand London facialist. "Warm a bean-size bit of balm in your hands, massage it in, and then remove it with a damp cloth for gentle exfoliation." The balm squad is passionate about Lacey's Cleansing Pomade ($100) and Eve Lom Cleanser ($80). Oils, like Josie Maran Argan Cleansing Oil ($32), are also a good choice, especially for sensitive skin. "Applying cleanser to completely dry skin will help it bind to dirt," says Gross. "Then hop in to the shower, where the steam opens pores and makes deep cleaning more effective."

All this talk of smog clog may make you want to take a Brillo pad to your face, but even nonsensitive types should be wary of overcleansing. While manual scrubs may feel satisfying, using them too often can lead to inflammation. "A safer bet for both aging and acneic skin is cleanser with glycolic or beta-hydroxy acids once or twice a week," Zeichner says. Try Dr. Dennis Gross's Alpha Beta Peel pads ($82).

The one must-have weapon for all skin types, however, is a sonic brush. Robb Akridge of Clarisonic, which recently introduced the Smart Profile ($265), explains how it works: "It oscillates at a frequency of more than 300 movements per second. It turns water into a garden hose to flush out pores." Clinique is also entering the brush fire with its Sonic System Purifying Cleansing Brush ($89.50); each bristle has a thread of silver that gives it antimicrobial benefits.

But short of living in a bubble, there isn't much you can do to prevent pollutants from invading your skin. "Day creams can help, but they're not 100 percent," says Vargas. The right antiaging product can combat the effects, though. "Look for products with vitamins C and E, lycopene, green tea, and grapeseed extract to fight free radicals," Gross says. Try Shiseido Ultimune Power Infusing Concentrate ($95), Natura Bissé Essential Shock Intense Cream ($115), or Sisley Black Rose Precious Face Oil ($235). It also couldn't hurt to use makeup that contains Detoxyl, a detoxifying ingredient found in Rouge Bunny Rouge Liquid Foundation ($55). There may be little we can do about our increasingly smoggy air, but with the proper routine your skin will glow even through the haze.